THE CIRCLE OF FIFTHS
The circle of fifths is a handy way of explaining how chords relate to each other. If you can get a grip on this idea, then all of a sudden you get an understanding of how chords work together. However, before we start please be clear that this is far from a full outline of music theory, and it doesnít try to be. Itís just a simple account for the benefit of folk who want to bang out a tune on a ukulele. So here goes.
Most simple chords consist of three notes, the key note, the third note in the octave and the fifth note. So the chord of C major consists of C, E and G. The chord of G consists of G, B and D, and so on. The important note is the third note in this series. For C that will be G and for G it will be D and so on. Itís known as the dominant note. You will notice that in most two chord songs you will be playing a chord for the key note and a chord for the dominant note. eg. C and G, G and D etc. In the diagaram you can select any note in the outside circle as the key note, and then you will find the dominant note as the next note round in a clockwise direction.
The whole shooting match gets more interesting with the introduction of a third chord, the subdominant chord. This is the note that is five notes below the key note. In the case of C it is F, and in the case of G it is C. You will find the subdominant note is the next note round in an anticlockwise direction. and that most songs in major using three chords will fall into line using the key chord, the dominant chord, and the subdominant chord. eg. C G and F, G D and C, etc.
A further helpful feature of the circle of fifths is appreciating the role of the relative minor. The minor key is the softer and more sensitive key, whereas the major key is bold and forthright. For every major chord there is a family bond with a minor chord. The reason for this is a relative minor scale shares all the same notes as its bolder major relative. Eg. The scale of G major has the following notes: G A B C D E F# G and the scale of E minor has E F# G A B C D. They are the same notes but starting from a different place. You will find that more complicated songs in any particular key might introduce the relative minor chord for the key. Eg. C G F and Am, G D C and Em, etc.
So, for any one key you can look to the circle of fifths and immediately see the important chords, the key chord, the dominant chord (the one to the right), the subdominant chord (the one to the left) and the relative minor (the one in the inner circle).
A song which demonstrates the glory of the circle of fifths is that old stager, Ainít She Sweet. It has a wonderful chord progression that takes a quick tour around the right hand side of the circle of fifths.
The last two lines of the first verse go:
Now I [C]
ask you [E7]
The key chord is C, and although it skips to E7 it moves to A7 (the subdominant of E) to D7 (the subdominant of A) to G7 (the subdominant of D) and finally to C (the subdominant of G) and thereby resolving the tune.
I refer to the four chords, the key chord, the dominant chord, the subdominant chord and the relative minor as a family. You will find that you can busk and improvise to your hearts content if you keep the chords within the family. Youíll probably also notice that when you want a turn around, ie. The note at the end of a phrase before you go onto the next piece it is usually the dominant chord.
So, busk around the circle of fifths and have fun.